Timer that can interact with context.object?
with a handler it may work

import bpy, os

ao = None

def h(s):
    # just for testing, normally i won't use global
    global ao
    o = bpy.context.active_object
    if(ao != o):
        ao = o
        print(ao)
    if ao.name == "Cam Small":
        return None

bpy.app.handlers.depsgraph_update_post.append(h)


but that doesn't really respond to the goal of the question